Magnetic chuck



J. L. MORAN.

MAGNETlC CHUCK.

APPLICATION FILED NOV.1l,1919.

. 349, 43 Patented Aug. 10, 1920.

2 SHEETS-SHEET 1.

I11 I\\ I X 15 12 11 120' 11 1? 12 15 J. L. MORAN.

MAGNETIC CHUCK.

APPLICAIION FILED NOV. 11. 1919.

1, 349, 343. Pa nted Aug. 10, 1920.

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Z2 uenzov d/mlljfi an. 3712 751 02: neg/5* JOHN L. MORAN, OF WORCESTER, MASSACHUSETTS,

ASSIGNOR TO HEALD MACHINE COMPANY, A CORPORATION OF MASSACHUSETTS.

MAGNETIC CHUCK.

Application filed November To all whom it may concern:

Be it known that I, JoHN L. MoRAN, a citizen of the United States, residing at Vorcester, in the county of \Vorcester and State of Massachusetts, have invented a new and useful Magnetic Chuck, of which the following is a specification.

This invention relates to a magnetic chuck and particularly to a face plate for a magnetic chuck embodying novel features of' construction.

It is the object of my invention to provide a face plate in which pole pieces of op posite plurality are disposed alternately and closely adjacent, and in which such pole pieces are held very securely in position.

With this object in View, a feature of my invention relates to a construction in which all of the pole pieces of one polarity are formed as a unitary structure, and all of the pole pieces of the opposite polarity are formed of separate pieces securely held in alternate arrangement with the unitary pole pieces. By such constructionI attain simplicity and economy of manufacture, and provide a face plate peculiarly adapted for the holding of a large number of small metal parts.

A preferred form of my invention as embodied in a rectangular chuck is shown in the drawings, in which Figure l is a plan view of the chuck;

Fig. 2 is a longitudinal sectional elevation .taken along the line 2-2 of Fig. 1;

Fig. 3 is a transverse sectional elevation taken along the line 3-3 in Fig. 1;

Fig. 4 is a detail perspective view of a portion of one set of pole pieces, and

Fig. 5 is a perspective view of one of the pole pieces of the opposite polarity.

Referring to the drawing, my improved chuck comprises a base 10, having a plurality of magnet cores 11 and 11 preferably formed integral with the base and each surrounded by the usual magnet coil 12. The adjacent coils are wound in opposite direc tions, thus providing a. set of cores ll of one polarity and set of cores ll of the opposite polarity alternating therewith.

The novel features of my invention are embodied in the removable face plate for the chuck, which comprises a rigid frame 13 having an opening 14 therein, and detach ably secured to the base 10 by studs 15. All of the pole pieces of one polarity are Specification of Letters Patent.

Patented Aug. 10, 1920. 11, 1919. Serial No. 337,137.

preferably formed as a single unitary structure, shown in Fig. 4, in which the parallel pole pieces 16 are connected together by bars 17 at their lower edges. The bars 17 are spaced apart and are each adapted to rest upon one of the cores 11 in the base 10.

Separate pole pieces 18 (Fig. are disposed between adjacent pole pieces 16 and each pole piece 18 is provided with depending projections 19 engaging the alternate cores 11 The pro ections 19 are of such length that the pole pieces 18 do not con tact with the bars 17 connecting the pole pieces 16. The projections 19 are preferably of dove-tailed shape, as indicated in Fig. 5, and the ends of the pole pieces 16 and 18 are also preferably beveled, as shown in Figs. 2, 4 and 5.

In assembling my improved face plate the two sets of pole pieces are positioned in proper spaced relation within the opening 14 in the frame 13 and all intervening spaces are then filled in with lead or other non-magnetic material.

The beveled ends of the pole pieces and the dove-tailed shape of the projections 19 aid in firmly securing the pole pieces in the frame 13 by the non-magnetic material and prevent possible outward displacement thereof and the engagementof the pole pieces with the magnet cores prevents inward displacement thereof.

lVith this construction it will be seen that I have provided a face plate having alternately disposed pole pieces of opposite polarity separated by relatively narrow portions of nonmagnetic material. Accordingly it is possible for small pieces of steel or iron to span the distance between two pole pieces of opposite polarity and to be held firmly on the face plate.

While capable of general application, this face plate is particularly designed for holding such small pieces which cannot be readily held onmany of the face plates now in use.

Having thus described my invention it will be evident that changes and modifications can be made therein by those skilled in the art, within the spirit and scope of my invention as set forth in the claims, and 1 do not wish to be otherwise limited to the details herein disclosed, but what I claim 1s l. A magnetic chuck, having, in combination a base having a plurality of magnet cores thereon, coils for said cores, and a face plate comprising an outer frame having an opening, a plurality of pole pieces forming a unitary structure with bars connecting the lower portions thereof and engaging certain of said cores of one polarity, and a plurality of separate pole pieces mounted alternately with the first mentioned pole pieces and above said bars and having lugs projecting downwardly between said bars to engage certain other of said cores of the opposite polarity, all of said pole pieces being rigidly held in spaced relation in the opening in said frame.

2. A magnetic chuck, having, in combination, a base, a plurality of magnet cores mounted thereon, coils for said cores, and a base plate comprising an outer frame having an opening, a plurality of spaced parallel pole pieces formed as a unitary structure with spaced connecting portions at its lower side engaging alternate magnet cores of one polarity, and a plurality of separate pole p1eces mounted alternately between said first mentioned po-le pieces and above said connecting portions and having downwardly extending projections engaging alternate magnet cores of theopposite polarity, said pole pieces being secured in said opening in said frame by a filling of nonmagnetic material.

8. A magnetic chuck, having, in combination, a base having a plurality of magnet cores thereon, coils for said cores, a face plate comprising an outer frame having an opening, a plurality of pole pieces formed as a unitary structure with integral bars connecting the lower edges of said pole pieces and engaging certain of said cores of one polarity, and a plurality of separate pole pieces mounted alternately with said first mentioned pole pieces and above said bars and having lugs projecting downwardly between said bars to engage certain other of said cores of the opposite polarity, all of said pole pieces being rigidly mounted in spaced relation in the opening in said frame, and the ends of said pole pieces being enlarged in their lower portions to prevent upward displacement of said pole pieces.

4. A magnetic chuck, having, in combina tion, a base having a plurality of magnet cores therein, coils for said cores, wound to provide alternate cores of opposite polarity, and aface plate comprising an outer frame having an opening, a plurality of spaced parallel pole pieces formed as a unitary structure with spaced integral connecting portions on its lower side engaging alternate magnet cores of one polarity, and a plurality of separate pole pieces mounted alternately between said first mentioned pole pieces and above said connecting portions and having spaced downwardly extending projections engaging alternate magnet cores of the opposite polarity, all of said pole pieces being outwardly beveled toward their lower sides and being secured in the opening in said frame by surrounding said pole pieces with a filling 0f non-magnetic material.

n testimony whereof l have hereunto affixed my signature.

JOHN L. MORAN. 

